I've got a few theories I thought I'd share
So with [Captain America: Civil War](tag:994409) fast approaching (Not really, it doesn't come out until May of 2016... :/ ) I thought I'd share with you a few things that I think would be cool, or that might happen in the movies to come, given some of the things Marvel has set up.
Let's talk Crossbones. He's probably one of my all-time FAVORITE Captain America Rogues, and here's why. He is monumentally important to Civil War for one, and I'm super pleased to hear that Frank Grillo has a multi-movie contract with Marvel! I'm going to be talking Civil War as in the comics, so here's my spoiler warning.
In Civil War, it is Crossbones who shoots Captain America, and opens the way for Agent 13 (Sharon Carter) to deliver the killing blow. It is unlikely that Marvel will be using the Death of Captain America storyline but...
... but the inclusion of the Brock Rumlow character in the Civil War movie makes me think that he will kill someone. My guess is as good as any of yours, but possibilities might be that the assassination attempt is botched and he does attempt to kill Cap... or maybe we'll see the Death of Spider-man story arc, not in Civil War, where Spider-man dives in front of a bullet to save Captain America. With Asa Butterfield as our new Spider-man, I don't know. He's on to do a few movies in joint effort between Marvel and Sony, but I don't know where those movies will fit in with the timeline of the MCU.
What Marvel has Set Up
In [Captain America: The Winter Soldier](tag:254973), we are introduced to a team called "STRIKE" at the beginning of the movie. It is led by Brock Rumlow (Crossbones). In the Comics, STRIKE was Britain's form of SHIELD, closely aligned with the Braddocks. Why is some random last name important? Well I'll tell you. Brian Braddock is better known as Captain Britain, and he has a sister named Elizabeth Braddock, AKA Psylocke. With the introduction of the Scarlet Witch and Quicksilver as "Enhanced", it would not be too far off to say that Psylocke, and maybe even Captain Britain will find a place in the MCU. In Agents of SHIELD, the Terrigen Mist has been confirmed to exist within the cannon of Marvel's cinematic, and television multiverse. Perhaps it will be revealed that the Mist is the cause of the mutation that made Scarlet Witch and Quicksilver, and it will be those mists that create Psylocke.
Captain Britain's storyline I think would tie in better with the announced Doctor Strange. Because Captain Britain got his powers through a magical symbol of power, the Amulet of Right. Maybe with the introduction of these two Hero-Brits we can see the characters of Albion, Lionheart, and maybe Union Jack, all prominent "Across the pond" characters. Brian Braddock in the comics has come into contention with Lance Hunter who we've seen on Agents of SHIELD. Canonically, Lance Hunter is the STRIKE commander and is seen briefing the British Superhumans on the Commission of Superhuman Activities out of the UK.
I was really glad to hear that Benedict Cumberbatch would be playing the Sorcerer Supreme. Not just because I'm a massive fan of BBC's Sherlock. We've been introduced to the Quantum Realm in Ant-Man... and I'm really looking forward to what's going to be done with it in the future. Doctor Strange is kind of a strange- *Gets the Death glare for terrible puns* Okay he's a weird choice when picking what comic book heroes get movies. But hey, everyone said that about Guardians of the Galaxy too and... it's one of my favorite movies. Ever. Not just comic book movie either. In general. Marvel has stated that Doctor Strange will be interdemensional, which we've seen 1. The Nine Realms from Thor, 2. The Quantum Realm from Ant-Man, 3. Basically Guardians of the Galaxy. Doctor Strange will have no shortage of dimensions to explore. I'm excited for that.
Infinity Stones (Rather what lies therein)
So we saw the Red Skull, Ronan the Accuser, and Malekith all killed by their respective Infinity Stones. But perhaps they aren't truly dead, just stuck inside of their stones, waiting to be released. It isn't unrealistic. In "The Guardians of the Galaxy Meet the Avengers" we see Adam Warlock pulling the Avengers and the Guardians into the Soul Gem. I think it is realistic to say that these three rogues could have been sucked into their Infinity Stones, or at least, Marvel could use that excuse as a scapegoat to bring back these villains. Maybe the Skeleton Crew or the Thunderbolts could get an appearance. Red Skull and Crossbones are there, Jack Rollins from Captain America: The Winter Soldier could have a slot, and some of the B-list villains we've seen in the MCU could be there too. We've also seen Baron Strucker, and we're eventually getting Baron Zemo. Who knows what direction Marvel will go.